Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease that is associated with insulin resistance and hepatic triglyceride accumulation. There is evidence to suggest that a low glycemic index (GI) diet can reduce glucose absorption, hepatic influx of glucose, and de novo lipogenesis. This review investigates the effect of low GI and glycemic load (GL) diets on hepatic fat mass, hepatic enzymes, insulin resistance, fasting blood glucose levels, and blood lipid panels in individuals with NAFLD. PubMed, Cumulative Index to Nursing and Allied Health Literature, and Web of Science were used in literature search. Search keywords included "glycemic index," "glycaemic index," "glycemic load," "glycaemic load," "nonalcoholic fatty liver disease," "NAFLD," "nonalcoholic steatohepatitis," and "NASH." Outcome measurements included hepatic fat mass, hepatic enzyme alanine transaminase (ALT), insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)], fasting blood glucose levels, and/or blood lipid panels. Four eligible studies enrolling 281 individuals with NAFLD were included. Both hepatic fat mass and ALT showed significant reductions from baseline in both low GI and GL diets. One study showed no change, and another study showed significant reductions in HOMA-IR. No significant reduction in fasting blood glucose level, triglycerides, high-density lipoprotein-cholesterol, or low-density lipoprotein-cholesterol was observed from baseline in both low GI and GL diets. Findings from the review suggest that low GI and GL diets may reduce hepatic fat mass and ALT in individuals with NAFLD. Future research of large-scale, randomized controlled studies using isoenergetic, low GI and GL diets for long term is needed to draw conclusionary results.
Keywords: ALT; glycemic index; glycemic load; hepatic fat mass; nonalcoholic fatty liver disease.